The US dollar is still at the centre of the world's financial system, and its importance isn't fading in the face of exaggerated claims to the contrary.

That reality has gotten lost as various commentators complain about the decline in the value of the dollar, particularly against the euro. Nevertheless, the dollar continues to dominate foreign exchange markets, US financial markets are the world's deepest and most liquid and Treasury securities remain the globe's premier risk-free investment. And, of course, the US is a market second to none - to which foreign companies supplied more than $2.2 trillion worth of goods and services last year.

Ignoring all that, President Hugo Chavez of Venezuela jeered after a November 18 meeting in Saudi Arabia of the heads of state of the Organisation of Petroleum Exporting Countries: "The fall of the dollar is not the fall of the dollar - it's the fall of the American empire."

More seriously though still off base, European Central Bank president Jean-Claude Trichet earlier this month described the decline in the dollar against the euro as "brutal," saying such moves are "never welcome". And on November 7 French President Nicolas Sarkozy told the US Congress that this country must support the dollar or risk starting a trade war.

Trichet, who had complained many times about the need to address major global economic "imbalances" such as the large US current account deficit, somehow overlooked that the euro- area countries had a $62.6 billion trade surplus with the US in the first nine months of this year.

That surplus was down from $69.1 billion last year, and the decline in the dollar - which always had to be part of the process of adjusting those imbalances - undoubtedly has been a factor.

Sarkozy similarly overlooked the $1 billion increase in the US deficit with France, which reached $10.2 billion over the same period. Trade war indeed.

And what does Sarkozy want this country to do to support the dollar? The Federal Reserve isn't about to raise its target for the overnight lending rate, which it cut to 4.5 percent at the last meeting of the Federal Open Market Committee, to shore up the currency.

Of course, he earlier had no luck arguing against a rate increase by the ECB on the grounds that the euro was becoming too expensive.

As for jokes, one attempt really wasn't very funny. A cartoon by Mike Luckovich of the Atlanta Journal-Constitution reprinted in the November 18 New York Times showed Treasury Secretary Henry Paulson, in the Oval Office with President George W. Bush, asking: "Can I get paid in euros?"

Actually, Zodiac SA, Europe's biggest maker of airplane seats, would like to get paid in euros.

Zodiac sells both to Boeing Co. and its European competitor Airbus SAS, the world's two largest manufacturers of commercial aircraft. It's hardly surprising that Boeing insists on paying its suppliers in dollars. However, so does Airbus because so many of its own sales are priced in dollars.

The US market is so important that many exporters to the US routinely price their products in dollars and accept whatever currency risk that may involve. In the current situation, many of the exporters are accepting lower profit margins in order to hold onto their market share. Zodiac's chief executive officer Olivier Zarrouati acknowledged in a November 16 press conference that his company is among them.

The dollar is just as central to world-wide financial transactions.

For example, the dollar was involved in 86.3 percent of last April's $3.1 trillion average daily turnover in foreign exchange markets, according to a survey by the Bank for International Settlements.

The vaunted euro, supposedly everybody's newest favourite, was in only 37 percent of the transactions. The Japanese yen, whose importance is fading, was in 16.5 percent, closely followed by the British pound with 15 percent. Because there are two currencies in each transaction, the sum of all the percentages is 200 rather than 100.

The focus on the cross rate between the dollar and the euro gives an exaggerated sense of the dollar's fall in value.

Check out the Federal Reserve's broad dollar index weighted according to US trade with other countries and adjusted for relative inflation rates. That index has averaged 86.83 so far this month, which is an 8.4 percent drop from November 2006. The decline over the 12 months prior to that was 4.5 percent.

The dollar has gone down 14 percent against the euro in the past 12 months.

The recent decline in the index is hardly unprecedented. The index base is March 1973 when it equaled 100. Since 1990 it has been as low as 84.23 in July 1995 and as high as 112.84 in February 2002.

At the OPEC conference, Chavez and Iranian President Mahmoud Ahmadinejad argued that the group should consider pricing oil in a currency other than the US dollar. The talk didn't go anywhere, and even if OPEC were to switch - which it has discussed occasionally in the past - it's not clear what the impact would be.

If OPEC required payment in euros, a buyer would just trade the dollar for euros and then pay the bill. If the oil exporting countries, which are accumulating large currency reserves, were to decide to hold more euro-denominated investments, they could do that easily without setting the oil price in euros.

(John M. Berry is a Bloomberg News columnist. The opinions expressed are his own.)